Method of solidifying crystallizable mixtures without substantial crystallization.



E'. I. DU PONT. METHOD 0T SOLIDIFYING GRYSTALLIZABLE MIXTURBS WITHOUT SUBSTANTIAL GRYSTALLIZATION.

APPLIOATION FILED JAN. 31. 1910.

Patented Oct. 31, 1911.

2 SHEETS-SHEET 1.

ATToRNEY P. I, DU PONT. METHOD 0F SOLIDIFYING GRYSTALLIZABLE MIXTURES WITHOUT SUBSTANTIAL CRYSTALLIZATION. APPLICATION FILED JAN. 31, 1910.

LGO'QYG., Patented 0011.31, 1911.

2 SHEETS-SHEET 2.

WITNESSES.- f! l IMI/ENT R gr Y 5 BY HMM-.7

ATTORNEYS.

i nooners.

oF NEW JERSEY.

UNITED STATES rarnisrrV energia,

FRANCIS i nu PoN'r, or WILMINGTON, DnLAWAnnAssrGNon To n. Lfu' PoN'r NEMOURS-POWDER. COMPANY, or vu'fILMINe'roN, DELAWARE, A coarona'roN METHOD or soLIDIFYING c1wsTaLLIzAnm: Mix'rmanslwrcrnour.smas'raN'rrAr.l

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Specieation of Letters Patent.

' ginalapiliication'led September 24, 1909, Serial' No. 519,318. Divided andI this application yfilled y January 31, 1910.

To all whom it may concern:

Be it known that I, FRANCIS I. DU PONT, a citizen of the United States, residing at Wilmington, county of New Castle,` and State of Delaware, have invented a new and useful Improvement vin Methods of Solidifying Crystallizable Mixtures `Without Substantial Crystallization, of which the following is a full, clear, and exact description, reference' being Vhad to thewaccompanying drawings, which form a part' of this specification.

In the manufacture of black powder from an initial mixture of the ingredients when in a dissolved, liquid, lor semi-liquid condition produced by solvents or heat or both, it is necessary to `return the material to la solid 'condit1on without substantial crystallization. It is also' necessary in the process to which -this application refers to do-this in such a way that in the return of the ingredients fromthe liquid condition,

masses canbe formed of any desired size or shape and of sufficient hardness to form what are known as grains of powder. Some of the ingredients of this powder are rendered soluble by a liquid, other ingredients by heat. I first subject the dissolved, liquid or semi-liquid mixture, to the action of heat and rubbing or abrasion. 'An apparatus by which this step may be carried out is described and illustrated yin Letters Patent No. 944,500, issued to me December 28th, 1909. This action will'have no effect u on such ingredients as are `brought to a llquid condition by heat, andwere it attempted to bringy to a solid condition by this operation all of the ingredients which are not brought to a liquid condition by heat, the material delivered would either be in the form'of dust or of lumps of insutlicient hardness, or more probably a mixture of such lumps and dust, which product would be altogether inferior, if not useless, for the purpose for which ordinary blasting powder is used.

The object of'my-invention is to bring the material, which is delivered in a liquid or semi-liquid condition by the apparatus described in my aforesaid patent, to a yplastic condition and to do this without substantial crystallization of the materials which are brought into the liquid state by solution, or of those materials which are Serial No. 540,951.

brought into the liquid state. by heat. The mass after admixture in a 'luid or semi-fluid condition is subjected to heat Vwliileworking suchr mass during saidtreatment. yThe eifect of this is to bring into a partially solid condition those ingredients -which are rendered liquid by a` solvent, the results being accomplished by the evaporationof the' solvent during a rapid agitation ofthe mass. This Patented oct. 31, 1911.l

treatment, however, does not have this eil'ect upon the ingredients rendered liquid by heat. For instance, take black powder, an example of the ingredients is 7 3 parts nitrate of soda, 16 parts charcoal and l1 parts sulfur,iin such com osition the 1iquid sulfur will not be solidi ed or partially solidified by this treatment. Also it is not desirable to carry this treatment far enough 4to solidify the nitrate of soda, because for the reason above given.

The treatment of heat and working just describedmay be carried on in an apparatus and in the manner described, illustrated and claimed in the patent before mentioned. y

The present invention relates to a process for completing the partial solidication, that is, that lstage ofthe solidiiication which is required for the formation of grains, these grains being cut or molded from a plastic mass'having so small a per cent. of moisture that further evaporation of this moisture will not produce crystallization..

I have disc vered that if I take the mixture after it as passed through the evaporator and form ,it into a thinA sheet, which sheet must be for the best results as thin as it can be formed, and when in such thin sheet, subjected to cooling action the matcapplication filed by me September 24th, 1909, Serial No. 519,318, of which this application is a division.

In the drawings: Figure 1 is a general view of my invent'ion, with some vof the parts in elevation and others in section.

Fig. 2 is a section on the line 2 2, Fig. 1.

Fig. 3 is a detailed View of a portion of the apparatus adjacent to the point of reception of the material upon the roller. Fig. 4 is an enlarged section of the mechanism for removing the powder from the carrying roller v and forming it into the ultimate sheet or ing roller e, which is revolved in the direction of the arrow. The peripheral speed of the rollers d and e is the same. The tendency of vthis roller e is to press thematerial in the chamber c onto the face of the roller d. On the other hand, the material is of such character that its tendency is to followthe roller e as well as the roller d..

In order to obviate this last mentioned condition I use' what I term a spreader and scraper f. This scraper and spreader f is pivoted and backed up by the spring 'g. This combined scraper and spreader f has a portion contactingwith the surface of the roller e to prevent the material following the roller e. As shown, this has a knife l edge. It is also provided with-a projecting lip f which is spaced a distance from the surface` of the 'roller d equal to the distance between the surfaces of rollers d land .e at their nearest point. By this arrangement the material is, by the action of the roller e, spread upon the roller d, and the thickness of the sheet determined by the distance between the rollers d and e. Further, the scraper and spreaderprevent the material following the rollere and also maintain the thicknessv of the sheet the same as that of the distance between the rollers. As stated, the roller `d isa skeleton roller,- having the internal chamber 5.

' h is a pipe leading from a source of water supply or cooling fluid, not shown. The pipe h passes through the hollow hub of the rollerd and connects with the pipe i, which p passes'up vertically inthe chamber 5, and

terminates in the branch .7','having the nozzles or sp'rayers lc. A

Z is a pipe leading from the lower portion of the chamber 5, connecting with the pipe pump. When water asses from the pipe h,

' under pressure, it is orced out through nozzles c and'sprayed against the inner surface of the roller d, thus chilling the surface of the ro d and chilling the powder strip as it passes around with thewheel. The rollend is driven. by the worm 1 and worm Wheel 2./ The water will flow by gravity to the bottom of the chamber 5, and is withdrawn by the pump, acting through pipes m and Z.

As stated before, the sheet from the roller d is too thin to be used in the subsequent steps in the manufacture of the powder into grains. necessary in this apparatus, mechanism for the purpose of forming this thin sheet into a sheet of proper thickness to be cut into powder gra1ns.`

Near the lower surface of the roller d I providel the rollers v0, p, and g. The roller vo revolves in the same surface direction and at the same surface speed as the roller d. The roller g revolves in the opposite direction and at a surface speed to be determined by the desired thickness of the ultimate powder strip, as will. hereinafter be more fully described. As these two rollers. g and o revolve in opposite directions the powder sheet upon the roller d will, when it reaches those rollers, be, by their reverse action, crowded between them into the space as shown. The scraper t, backed up by the spring u, prevents any" powder passing beyond the roller g. Between the rollers o and g is the roller p revolving in a direction opposite tothe roller g. The material crowded between the rollers o and g is prevented from passing out betweenlthe rollers o and p by means of the scraper and cleaner o, backed up by the spring w. As the draw- ,ings show, the scraper and cleaner v contacts with the roller 0, as that is the roller which will tend to carry the material around in /the direction between the rollers o and p. In like manner, the scraper and cleaner t contacts with the surface of the roller d, as that roller is the one which 'will tend to I therefore have provided, as is carry 0E and prevent the material being brought into the space between the rollers g and o. The rollers p and g are separated from each other at a distance equal to the thickness of the desired powder strip and their peripheral velocities are determined the scraper f, has the scraping surface or edge, which contacts with the roller g, and ,the projectingv lip e 'which is spaced froml the roller p a distance equal to the distance -between the rollers p and g at the nearest points said rollers approach each other. By this construction the powder mass in the space between the rollers o and g will pass out between the rollers p and g and will be prevented from following the roller g by the scrapin surface ofthe scraper and spreader z, and e maintained by the lip z at the proper thickness. The action is thus a formative one between the rollers p and g, these forming a spreading and holding action between the 11p a and the roller p.

Finally, the powder strip is released from the roller p by means of the scraper a', the scraping surface of which contacts with the roller p beyond the point of action of the v lip z. This scraper .fr is also provided with a projecting lip m to carry the powder fully clear of the scraper itself so that it will move or pass free from said scraper. The scraper a; is held in operative position by the spring y.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is: X

l. The hereinbefore described methodof solidiying crystallizable mixtures rendered liquid or semi-li uid by solvents and heat,

' Without substantial crystallization, which consists in subjecting the mixture to the action of heat and rubbing to remove theA solvents, then forming said material into a i v thin sheet, then chilling said sheet.

2. The hereinbefore described methodof v solidifying crystallizable mixtures rendered liquid or seml liquid by solvents and heat, without substantial crystallization, which consists in subjecting the mixture tothe action of heat and rubbing to remove the solvents, then forming said material into a the desired thickness.

4. In the method of solidifying crystallizable mixtures of the character described Without substantial crystallization, forming the mixture into a thin sheet, chilling said sheet, then forming material in to a sheet of greater thickness than the first mentioned sheet. i

In testimony of which inv'ention, I have hereunto -set my hand, at Philadelphia, on this 28th day of January, 1910.

FRANCIS I. u PONT.

' Witnesses: M. M. HAMILTON, A. M. URIAN. 

